The long range objective of this grant proposal is the definition of molecular structure-function relationships of certains proteins involved in blood coagulation ad fibrinolysis. The following projects are being emphasized: 1) the localization of the Aalpha-chain crosslink sites in the fibrinogen molecule is still being pursued; partial sequences of several peptides have now been delineated and it is fairly clear the the alpha-chain contains two acceptor sites and two donor sites which are widely spaced; further work is being done on the isolation and identification of crosslink peptides from fully crosslinked fibrin; 2) the definition of the molecular structure of the human factor VIII (antihemophilic factor)/von Willebrand factor is being pursued; it is intended to focus on the importance of the carbohydrate moiety on this molecule with respect to its being involved in either activity; and 3) the stdy of the significance of the two forms of plasminogen present in human plasma. The undersigned agrees to accept responsibility for the scientific and technical conduct of the project and for provision of required progress reports if a grant is awarded as a result of this application.